Optical and electrical properties of vanadium pentoxide films prepared by RF reactive magnetron sputtering

Vanadium oxide (V2O5) films were deposited on sapphire substrates by Radio Frequency (RF) reactive magnetron sputtering at sputtering time of 15 min, 25 min, 30 min and 45 min. The film structures, film thicknesses, surface morphology, electrical and optical properties were studied at different sputtering time and other experimental parameters unchanged. The results indicate that the deposited films are polycrystalline V2O5 films on (001) preferred orientation. With the increase of sputtering time, crystallization behaviors become stronger, the grain sizes are larger, and the surface roughness values are reduced gradually. Moreover, phase-transition temperatures and temperature ranges are increased while the electrical mutation properties are reduced. The transmittances of the films (thickness of 350 nm) in a middle-infrared band were detected at high and low temperatures. The results show that the rangeability of transmittances (wavelength of 5 μm) is as high as 74% which ranges from 81% at 25℃ to 7% at 300℃. All the transmittance ratios before and after phase transitions are between 9-13, showing a very prominent optical-switching property. ©, 2015, Chinese Academy of Sciences. All right reserved.